Oh wow I believe those may be broilers. I have never seen a chick grow like that. But I have not had broilers. Personally I would sell them off as soon as weaned off heat and say they could be broilers to the buyer as if they are, keeping them to a full long life is painful for them I have read...
http://www.cacklehatchery.com/cornishcrosspage.html
Cackle has a video of baby Cornish cross chicks.
http://www.feathersite.com/Poultry/CGA/Broil/BRKMeat.html